Terrorism and crime are potential security risks at airports and on airplanes. To mitigate these risks, passengers and cargo are screened for potentially dangerous material, such as bombs and weapons, prior to being placed on an airplane. For example, cargo is often screened by a scanning machine, such as an x-ray machine, that is positioned over a conveyor belt on which the cargo travels. Typically, an opening into the scanning machine is narrower than the conveyor belt, such that cargo that is too wide or off-center on the belt is unable to enter the scanning machine.
Off-center cargo can be directed into the scanning machine using guide rails. Although such guide rails effectively reposition most cargo, some cargo, such as duffel bags, tends to ride the guide rail through the scanning machine opening and then to shift back to the edge of the belt once the support of guide rail is no longer provided. When such cargo is scanned from overhead by the scanning machine, only a partial image of the entire piece of cargo may result. When this occurs, the cargo normally must be removed from the conveyor belt and manually searched by airport security personnel.
Cargo that is wider than the opening into the scanning machine may block the opening, causing subsequent cargo to accumulate on the conveyor belt. When the opening into the scanning machine is blocked, airport security procedures typically prescribe removing all of the cargo that accumulated on the conveyor belt and manually searching each piece by hand.
Manual searching of the type identified above consumes undue time of airport security personal and delays cargo from being loaded onto the airplane, thereby increasing the cost of airline travel. It can therefore be appreciated that a need exists for a solution that eliminates or at least reduces the need for such manual searching.